In multichannel optical communication a multiplicity of channels (often up to 256 channels) carrying information is employed. Each channel carries information imposed on a modulated carrier optical signal within a relatively narrow range of wavelengths—typically a wavelength range between 0.1 Å and 25 Å. Thus as shown in FIG. 1 a series of channels, 7, 8, 9, and 10 (each represented by a spike corresponding to its center wavelength) comprises the signal carrying capacity of an illustrative optical communication system. Depending on the system, the longer wavelengths travel faster than the shorter or the shorter faster than the longer. Assuming the longer wavelengths are faster, a pulse in a particular channel after traversing a portion of the optical communication system would spread to broaden the pulse. Generally, dispersion compensators are employed to remove this pulse broadening within each channel.
Newly proposed systems such as discussed in Brener, I. et.al. (2000) “Cancellation of all Kerr Nonlinearities in Long Fiber Spans Using a LiNbO3 Phase Conjugator and Raman Amplification,” Optical Fiber Communications Conference, Post deadline Paper PD 33-1, have contemplated the use of OPCs in addition to other devices such as distributed Raman amplifiers. An OPC has the effect of inducing a conjugation of the phase of a signal and has been contemplated for use to reduce the problems associated with nonlinear effects in optical fibers. As more devices are added to optical communication systems the combined effect on a signal especially in a multichannel environment becomes complex.